The “Jump and Watch” display, sometimes called “Make Your Own Earthquake”, is very popular in museums, universities and science fairs. Below, we have basic instructions and suggestions to help you make your own “Jump and Watch” earthquake display.
Supplies
IRIS has a limited supply of geophones that can be given away for jump and watch displays. If you need a geophone (pictured below) please contact Wendy Bohon at bohon@iris.edu.
Setting up the geophone
Each geophone has 2 large bundles of wires; 3 wires per side. Some combination of 2 of these 6 wires will show a resistance across them of 100-120 ohms (this can be measured with a voltmeter). Please note that this could be 2 coming out of the same end or one coming from one end and one coming from the other end, and it could be any combination of colors. Once you find the combination of wires that shows a resistance of 100-120 ohms you strip those wires and hook them up to the DataQ Channel 1 + and - ports. Alternately, to provide a longer lead you can purchase a terminal strip for this purpose (Shown in the figure showing the set up). As a further test, you can also look at the voltage across the leads, and you should see a 20-40 millivolt signal when you shake the geophone. After the geophone wires are attached to the DataQ DAC,place the pointy end of the geophone into the flowerpot filled with sand. DO NOT plug the USB cable into the DataQ DAC and the computer until after downloading and installing the software described below.
Digitizer instructions
You can experiment with some of the view options (grid, annotations, etc). Once you decide you like a particular view, there is a menu option to save the configuration and the system will start that way the next time.
*Windaq software only runs under the Windows operating system. However, it also works on a Mac machine by running a Windows emulator such as Parallels.
**It is important that the geophone in the flowerpot has good coupling with whatever surface the visitors are jumping on in order to show a clear signal. If the signal is too small jumping directly on the floor, you may need to facilitate this coupling by placing the flowerpot on one end of a mat or carpet and having visitors jump on the other end.
Total cost - $300-$1000 US
